Thing Explainer

"This machine checks whether you have a piece of metal with a certain shape. If you do, it lets go of whatever it’s holding on to. People put these machines on boxes, doors, and cars to try to control who can open or use them.What’s interesting about these machines isn’t really the machine itself. There are lots of different kinds that work in different ways, but they’re all the same in one way: They try to put people into groups.By checking whether someone has a piece of metal that’s the right shape, this machine is really a way to try to tell whether people are who they say they are. It’s an idea—about which people should be allowed to do something—brought to life in metal."